NONPROFIT · WE TEACH. WE DON’T BUILD.
Home of the Super Energy-Efficient & Healthy Home (and Building)
Build it right or fix it right, once, for the next 100 to 250 years. If you are building for the generations to come, you are in the right place.
Shop Brian's books → Try the free cost calculator →
52 years of building · #3 Amazon Energy Efficiency bestseller · Real jobs, real photographs
Pick the path that fits what you’re working on.
Build a New Home / Building
The decisions you make on paper set your heating bill, your comfort and your repairs for the next hundred years. Most of the costly mistakes happen before the first shovel. I’ve designed more than 750 buildings and made those mistakes so you don’t have to. Learn what to ask before you sign anything.
Inside: THE BOX, the $49 playbook and checklist. The free calculator that shows what a better wall costs on your own building. Real wall and roof R values. A field guide that follows real houses and buildings through every stage, in more than 150 photos. And a way to talk to me about your plans before you build.
Learn & Teach
Field guides, courses and Carbonless 2126, forty lessons that follow a building from the dirt to the person living in it a hundred years from now. Plain English. No sales pitch. For homeowners, builders and the people who teach them.
Start with the first course free. Then pick the book or course that fits where you are: THE BOX, the Thermal Break guide, the field guides, or the audio course you can listen to in the truck. Carbonless 2126 is 40 courses that cover the whole house, and each one builds on the last.
Fix or Remodel a Home / Building
Your house is drafty, damp, or the bills are too high. Most people rip out the wrong thing and pay for it twice. I’ve walked through thousands of houses like yours. Find the cause first, then fix it once, the right way.
Inside: real photos of rot, mold, wet walls and a window ready to fall out, so you know what to look for. Then the books that show you how to fix it from the inside or the outside, the wall and roof numbers your HVAC contractor needs, and a way to talk to me about your house.
Join Carbonless
Take a seat at the Carbonless Roundtable: 26 gatherings a year with builders, owners and building professionals learning from each other. Bring your questions and hear what’s working on real jobs across North America.
Members get all 40 courses of Carbonless 2126, the Roundtable and its recordings, the digital field guides and the Wall and Roof Assembly Library. Members can also be listed in the Carbonless Directory. Homeowners, builders, remodelers and inspectors all sit at the same table.
THE CARBONLESS ROOF LUNG SYSTEM
Up to 48 degrees Mother Nature never got into the house.
Summer, 2 in the afternoon. The sun had been beating on that roof for about 4 hours. The shingles hit 141°. The ZIP wall in the sun: 109°. The bottom of the sheathing, under the Roof Lung: 93° to 99°. Checked with an infrared thermometer. Those are the photos below.
Europe calls it a cold roof. No fans, no power. Air moves between your roof and your insulation and carries the heat away before it ever gets in. I don’t just teach this. I live in it. My house runs at 45% humidity inside, and every guide shows you exactly how I did it.
Whether your utility bill is $200 or $2,000 a month, you can’t budget for what it will be in 30 years. Every roof is different. I’ve never done two the same. So you have two ways to go:
Learn it yourself: the Field Guides → Talk to Brian about your roof →
The cutaway: roof deck, the air gap, then a new nail base and underlayment on top. This is one of 10 different versions of the Carbonless Roof Lung System. In 2026, each one had to be designed for what was already there, and most new construction needed some custom design work too. That is why consulting is available, so you understand what is going on with your roof and why.
Outside: the ZIP wall in the sun reads 109.1°. The shingles read 141.0°.
Inside, under the Roof Lung: the bottom of the sheathing reads 93.1° and 98.7°.
A REAL JOB
The hot roof that went wrong.
An architect tried to stop the ice dams with a hot roof: closed cell foam sprayed on the bottom side of the roof deck. But nobody fixed the heat getting out through all the framing. Six years later they still had 4-foot icicles, heat tape on the roof, and $500 a month every winter. That is when they called me, and Carbonless designed the fix: the Roof Lung.
The hot roof. Closed cell foam on the bottom side of the roof deck. The framing still leaks heat.
Snow melting from underneath. Heat getting out of the house.
4-foot icicles over the windows, every winter.
The fix. Same roof, frosty morning. Before and after the Roof Lung.
Before the Roof Lung. You can see every truss in the frost. That is heat getting out of the house.
After the Roof Lung. You can’t see the trusses anymore. The heat stays in the house where it belongs. No snow yet this year, so this is our first after photo. More coming this winter. I won’t know for sure until 2027, but I’m 99% sure this one is a win. I also won’t know what it does to the utility bill for a full year. My estimate is about $100 a month or more.
Justin, Visten Group
CARBONLESS 2126
Every house, every building, every project, followed for 100 years, one course at a time.
A house is not built once and done. Over 100 years, the same house may be refinanced 20 times, insured by 20 different companies, and have title insurance sold on it 25 times. With a buying side and a selling side every time it sells, as many as 50 realtors could touch it.
Every trade touches it too: the landowner, the developer, the surveyor, the banker, the architect, the builder, the framer, the insulation contractor, the HVAC contractor, the inspector, the remodeler and the family living inside. Most of them never learned the same thing. That is how one person’s mistake becomes the next owner’s problem.
Carbonless 2126 is 40 courses, 78+ hours of continuing education, that put all of them at the same table. It follows a building from the dirt forward:
The land and how it gets developed
The site, the soil and the water
The plan and the design
The money: financing, insurance and the real cost to live there
The foundation, walls and roof
Air, moisture and mold
Heating, cooling and fresh air
Getting it built and inspected
Testing it and writing down what was done
Living in it, fixing it and passing it on
Each course is two hours or more of real education, built from real jobs. Pass its 20-question test with 80% or better and you get a Record of Completion with your name on it.
The first course is free. Start there, and see the whole table before you spend a dollar.
Carbonless is not accredited by a licensing board. Many boards let you report continuing education yourself, so ask yours whether it counts.
Brian Iverson, founder of Carbonless, also wrote Hammerdahl, a novel set in the year 2126. It looks back at the decisions we make today and how they affect the people living 100 years from now.
OUR MISSION
Affordable Housing matters.
Affordable Living matters more.
Carbonless is a nonprofit. We teach. We are not a general contractor, a homebuilder or a remodeling company, and we don’t do construction work. You and your builder do the building. I help you understand it.
I want the same thing for your family that I want for my own children and grandchildren. A home you can pass down. One that is comfortable, healthy, affordable to live in and built to last. And if you sell it someday, I want the next family to get a house built with care, not a pile of hidden problems.
I never want you calling me years from now saying, “We’ve got mold in our house. What went wrong?”
That’s why I teach the building envelope, moisture, insulation, fresh air, airtightness and the construction details that get skipped. I’ve spent 52 years in the field and made the mistakes so you don’t have to. I’ll tell you what I’ve learned and help you make your own decisions.
Brian Iverson, Founder
Talk your building through with Brian
Bring your plans, your problem or your questions. I have nothing to sell you but what I know, and one conversation can save you thousands.
I have been on about 25,000 jobs as a realtor, an architectural designer, a remodeler and a carpenter. Today I consult every day, and most of what I see is damage from something that was done a long time ago. A house or a building can only be fixed as well as the work that was done before it. That is why the first conversation matters.
New here? Try the first course of Carbonless 2126 free.
The Field Guides
Real buildings, real photographs, in the order the work happens.
What you get in every field guide
✓ Hundreds of photographs from Brian's own job sites
✓ Every step in the order the work actually happens
✓ Written by Brian Iverson after 52 years of building
✓ Instant digital download, or a hardcover for the truck
The Super Energy-Efficient & Healthy Home Field Guide
Follow real houses and buildings through every stage of construction, in more than 150 photographs. They come from years of real jobs and five phones full of about 50,000 photos and reels. The same steps work at any size: a starter home, a big custom house, a barndominium, a shop, or a building you are fixing or remodeling.
Digital $199 (instant download) · Hardcover $299
The Retrofit & Remodel Field Guide — The NightMare
Nearly 200 field photographs from more than 25 real projects. Find out what the building is telling you before you open a wall.
The main story: a family paying $800 a month for utilities was quoted $46,000 to replace two HVAC units, not even the ductwork. New equipment alone would not have brought that bill down. Instead they are adding thermal breaks inside and out and fixing what was done wrong. Two additions were torn off because replacing them cost less than fixing them. Their new quote to replace both systems is $21,000, and the goal is to bring the bill from $800 a month down to about $200.
Digital $199 (instant download) · Hardcover $249
Start Here
Start with the free calculator or the $49 book. Go deeper when you are ready.
THE BOX
Complete Edition. New construction, retrofit and remodeling in one book, with both checklists. About 137 pages and 20 real job photos. It shows how houses get sick with mold, moisture and rot, and what to ask before you build, remodel or buy. Start here before you build, buy or fix a house.
$49 · instant download
THE DIFFERENCE Calculator
Before you spend a dollar, see what it costs on your own building. Type in your building size, your windows and doors, and your utility bill. It shows what a better wall costs, what that adds to your mortgage each month, and what could be left over.
Free · instant download
How to Make a Thermal Break on the Inside of Your Home
For the house you already own. The actual method for adding a thermal break on the inside of your walls, step by step, in 30 chapters. Read it before you open a wall.
$169 · instant download
For the little ones
Beev’s Hammerdahl™ Stories
Follow Beev the beaver and friends through twelve months of adventures in Hammerdahl™. Read-aloud, ask-along picture books, one for every month of the year.
Can you spot Dewey and Pepi hiding on every page?
$7.99 each, or six books for $47.94
Meet Beev and friends →FROM A REAL JOB
A mountain home
It looked like a beautiful house.
Built in 1988. The roof is SIP panels made with beadboard foam, not the rigid insulation we use today. From the floor, that wood ceiling looks perfect.
Then you look up close.
The roof leaked. And there is tar paper on the inside and tar paper on the outside, so the foam is in a sandwich with no escape hatch for moisture. Add the moisture people make just living in a house, cooking and showers, and from what I saw, the beadboard soaked it up.
Houses don’t fail fast. They fail slow.
It’s a second home and the owners aren’t there often. Nobody looks up. My best read is that sometime while they were gone, the foam reached its saturation point and started to fail. We still need moisture readings to confirm it. Now there’s mold, mildew and a little rot.
The repair I would recommend: open the roof at the peak and repair it, then put the Carbonless Roof Lung System over the top and finish with a metal roof. That’s how I would fix this one, once the testing confirms what we’re looking at.
The vent tells another story.
The air conditioning blows air out at about 55 degrees, and it was 70% humidity inside the house. When that cold metal meets damp air, you hit the dew point, and water forms right on the vent boot. That’s most likely what feeds the mold around it.
What I would recommend: two dehumidifiers, one on the second floor and one in the basement, plus a two-stage furnace to keep the air moving.
Not sure what’s going on in your house? Find the cause before you spend the money.
What does your house really cost you every month?
Everybody asks what it costs. Every house is different, but you have to start somewhere. Get THE DIFFERENCE Calculator, free. Type in your building size and your bill, and see what a code-built wall costs you next to one built right.
REAL HOUSES. REAL PHOTOGRAPHS.
What You Can’t See Matters Most
Most of what decides how a house performs disappears behind the walls. These photos come straight from the courses in Carbonless 2126, so you can see it before it gets covered up.
New does not mean dry. Course 34.
Cooling makes water. Course 35.
Blocking before drywall. Course 38.
What You Don't Know About a Building Can Cost You for the Rest of Your Life.
I'm Brian Iverson. I started in construction at 14. In 52 years I've developed about 3,000 acres into more than 3,000 lots, closed more than 3,000 real estate transactions, and represented a bank through about 3,000 foreclosures. I've built 24 miles of road, designed more than 750 buildings that were built, and remodeled or retrofitted more than 300 more. I've been a Minnesota Certified Energy Auditor since 1979. Along the way I made mistakes that cost me millions. I can't get that money back, but I can help you avoid them.
Carbonless 2126 is forty short courses. A Stick is what everybody else calls a module or a course: one lesson, two hours or more, with a 20-question test at the end. Pass with 80% and you get a Record of Completion. We call them Sticks because a beaver does not build a dam with one stick. He uses lots of them, and it takes lots of sticks to build a house that lasts 100 to 250 years. All forty together are 78+ hours of education that look at a building from all Sixteen Seats at the table, from the landowner to the person who will live there a hundred years from now. I tell you exactly what is in every Stick. No products to sell. Just better decisions. The first course is free.
Higher Education for the Next 100 Years.
Welcome to Carbonless.
Building to code is the starting point. It doesn't have to be the finish line.
A home or building can be designed to use far less energy, cost less to operate, be healthier and more comfortable, and last for generations.
That starts with getting the building itself right — the walls, roof, foundation, windows, doors, air control, moisture control and thermal control.
Carbonless exists to teach you how.
Use less energy. Lower your utility bills. Live healthier. Build it to last.
Carbonless 2126
Higher Education for the Next 100 Years. Build it for the person not born yet.
Forty short courses that follow a building from the dirt to the person who lives in it a hundred years from now. Land, money, design, the build, testing, and the people at every seat at the table.
One construction mistake can cost more than your entire education. Each course ends with a test and a record of completion you may be able to self-report for continuing education where your board allows it.
The first course is free. $100 per course, or $3,900 for the complete program. Institutional price: $6,000. Your courses live on courses.carbonless.org: enroll there, then log in anytime to pick up where you left off.
Learn It Your Way
Listen in the truck, look it up on the job.
Super Energy Efficient Building Audio Course
14 narrated modules on how a building really works: heat, air, moisture, walls, roofs, windows and HVAC, in plain English. Lifetime access.
$99
Wall and Roof Assembly Library
867 verified whole-wall R and U values for walls, roofs and rim joists. 2x4 and 2x6, 16 and 24 inch on center, metal studs, every common insulation. U.S., Canadian and European values.
$299
CARBONLESS 2126
What's inside Carbonless 2126?
A Stick is what everybody else calls a module or a course. One lesson, two hours or more, with a 20-question test at the end. Pass with 80% and you get a Record of Completion.
We call them Sticks because a beaver does not build a dam with one stick. He uses lots of them. And it takes lots of sticks to build a house that lasts 100 to 250 years.
Carbonless 2126 is 40 short courses, 78+ hours of education, grouped into eight stages that follow a project from the land to the person who lives there in 2126. The first course is free. After that, buy them one at a time for $100, a stage at a time for $500, or get all of them for $3,900. See what is in each stage and who it is for →
JOIN CARBONLESS
Why Join Carbonless
People join for one reason. They want the whole education.
Land development. Real estate. Mortgages. Insurance. How mold grows and how to keep it out. How a building gets built right, from the dirt to the family living in it a hundred years from now.
Right now, half of the people joining want to sit across the table from a family and explain how to build a house where mold has no place to grow. That takes more than one class. It takes all of it.
As a member, you get:
All 40 courses of Carbonless 2126, the complete program.
A direct line to Brian Iverson, and to every other member.
A seat at the Carbonless Roundtable, 26 gatherings a year.
A listing in the Carbonless Directory.
All of it for as long as your membership is active.
Every member agrees to help the others out. If you run into a problem on a house, you are not on your own. You have Brian and the whole membership behind you.
$6,000 to join, then $99 a month for the Roundtable and the Directory.
Help us teach the next family.
Carbonless is a 501(c)(3) nonprofit. Every gift helps put plain-English building education in front of more people.
A PRACTICAL GUIDE TO BUILDING SMARTER, MORE EFFICIENT, AND SUSTAINABLE STRUCTURES.
“The book explores sustainable living through the concept of "thermal living," focusing on energy efficiency and reducing reliance on fossil fuels. Iverson offers practical solutions and encourages a mindset shift towards more environmentally conscious choices. The book is accessible, blending science and real-world examples to show how we can live in better harmony with the planet. Overall, it's a timely and engaging read for anyone interested in sustainability and the future of energy. Highly recommend this book!”
Consulting with Brian
Talk your building through with Brian before you spend the money. Bring your plans, your questions, or your problem.
Hammerdahl™
A Year of Family, Invention, and a Brighter Tomorrow
Thanksgiving, 2126. The whole town is coming to the table. A Brian “Bapa” Iverson original novel, set in a small Nebraska town one hundred years from now, in houses built the way Carbonless teaches. Book One. Hardcover and paperback available now.